The present invention relates generally to automotive windshield wipers and more particularly to a system for removing accumulated ice deposits therefrom.
The effectiveness of a windshield wiper in shedding precipitation from a windshield is severely limited by ice or snow build-up on the flexible rubber blade which sweeps across the glass surface. Gradually, the ice works its way between the cleaning edge of the blade and the windshield and, if its spread remains unchecked, the blade eventually loses all direct contact with the windshield. This totally neutralizes the squeegee cleaning action of the blade. In the midst of a raging blizzard, such a condition can pose dual safety hazards: severely restricted visibility, and a recurring need to stop the automobile in unfavorable conditions to chip away manually the build-up. Vibrations and stresses induced by the normal oscillatory wiping motion of the blade are usually insufficient to check the bothersome accumulations.
There are schemes known to the prior art for deicing windshield wipers or the adjacent windshield surface. The disclosure of U.S. Pat. No. 3,058,141, which is addressed generally to the problem of maintaining proper contact of a wiper blade with a curved windshield surface, alludes to the possibility of a defrosting action occuring due to the escape of air through nozzle openings in the wiper blade element. U.S. Pat. No. 3,371,368, also disclosing a structure for forcing a blade more securely against a windshield, shows holes on the outer surface of the blade which communicate with a hollow channel inside the blade to allow application of warm air against the windshield. However, although this warm air may be useful in deicing the windshield, there is no indication that it is effective in preventing ice build-ups on the blade itself.
Therefore, it is an object of the present invention to remove ice build-ups on the exterior of windshield wiper assemblies, even during operation thereof, and to do so in a simple, reliable and efficient manner.
It is a further object of the present invention to provide such a system, which can be adapted readily and economically to presently existing windshield wiper structures.